This movie has already broken records. It holds records for the highest ever midnight opening for a film ($8 million), the best opening day for a horror movie in the United States ($26.2 million) and the highest opening for any film in October.

Essentially it is a prequel to the two previous Paranormal Activity films. It opens in 2005 with the discovery of a box of videotapes. The rest of the movie consists, allegedly, of the footage on the tapes. In 1988, Dennis (Smith) decides to set up video cameras to record the strange events occuring in the house he shares with his girlfriend, Julie (Bittner) and Julie's two young daughters, Katie (Csengery) and Kristie (Brown). The events appear to centre on the two girls, in particular Kristie who holds long conversations with her invisible friend "Tony". Over the subsequent nights the severity of the events quickly escalate and Dennis comes to realise that he and his family are in serious danger.

The set up of the scares in the Paranormal Activity movies mostly consist of long periods of silence and inactivity as the cameras record the characters sleeping, and then a sudden SHOCK as a door SLAMS SHUT or something FALLS or is THROWN. It is very simple, but it is quite effective, because it is startling to have a sudden loud noise after a long period of total silence. This is of course a trick that horror film-makers have known for years. The cameras are set up in a way to give the widest possible field of vision, so I found myself scanning the image constantly on edge for something to happen. it is the fact that you are constantly expecting something. The horror events when they do come are quite subtle, for example a figure draped in a white sheet appears behind the babysitter late at night. You might think it's one of the two girls. Suddenly the sheet falls to the floor, as if whatever was inside it has vanished into thin air.

These "fake documentary" films really divide audiences, because a lot of people find them terrifying, whereas a lot of others don't find them scary at all. I think if they are done well they can be very effective. Personally I quite enjoyed Paranormal Activity 3, and there were a couple of really effective scares. One sequence in particular drew a lot of gasps and screams from the audience I saw it with, which very rarely happens with horror movies. However, it does suffer from a few long patches of dullness. Also there is not much of a story here and what there is is hardly original. However, there are just enough jolts to make it worthwhile checking out.